diff --git a/website/source/docs/agent/options.html.markdown b/website/source/docs/agent/options.html.markdown
index 9d25da28d..bc371abbb 100644
--- a/website/source/docs/agent/options.html.markdown
+++ b/website/source/docs/agent/options.html.markdown
@@ -658,7 +658,7 @@ Consul will not enable TLS for the HTTP API unless the `https` port has been ass
 * <a name="retry_join"></a><a href="#retry_join">`retry_join`</a> Equivalent to the
   [`-retry-join` command-line flag](#_retry_join). Takes a list
   of addresses to attempt joining every [`retry_interval`](#_retry_interval) until at least one
-  [`-join`](#_join) works.
+  [`-join`](#_join) works. The list should contain IPv4 addresses without port number or bracketed IPv6 addresses with the Serf LAN port number also specified — for example: `[::1]:8301`.
 
 * <a name="retry_interval"></a><a href="#retry_interval">`retry_interval`</a> Equivalent to the
   [`-retry-interval` command-line flag](#_retry_interval).